1.2 Criteria Flashcards
How is DNA replicated?
semi-conservatively
What enzyme is required for DNA replication?
DNA polymerase
What is a primer?
short strands of nucleotides
What is the enzyme Helicase’s function in replication?
Unwinds the DNA double helix and breaks the hydrogen bonds between complementary base pairs
What must a primer do before replication can start?
The primer must bind to the 3’end of the single stranded template DNA
What does DNA polymerase add and how does it work?
DNA polymerase adds DNA nucleotides oly to the 3’ (deoxyribose) end of the new DNA strand. i.e it works in one direction.
What strand is replicated continuously?
The leading DNA strand
What strand is replicated in fragments?
The lagging strand
What is the name of the fragments that are replicated on the lagging strand?
Okazaki fragments
DNA nucleotides are joined together by what?
Ligase
What does PCR amplify?
Short sections of DNA
What is required that is complementary to specific target sequences at the two ends of the DNA to be amplified?
Primers
PCR: Why is the DNA heated to between 92-98°C?
To denature the DNA which separates the strands
PCR: Why is the DNA cooled to between 50-65°C?
To allow primers to bind to the target sequences.
PCR: Why is the DNA then heated to between 70-80°C?
To allow heat tolerant DNA (taq) ploymerase to replicate the DNA sequences.
